Various techniques of spectrophotometry of liquids, such as milk, are already known. In particular, spectrophotometry techniques that are based on measurement of the light transmitted through the liquid and detected by detectors comprising photo diode strips. Such techniques are used, inter alia, for estimating the quality of milk.
In order to estimate the quality of milk, information about various component parts of the milk is acquired and checked. Such information is useful, inter alia, for different aspects of the herd management. The various component parts may include fat, total protein, casein, lactose, somatic cells, blood, progesterone, amino-acids urea, and nucleic acid. The information may be used as an economic indicator of the overall milk quality. For example, the fat and protein content may be used for determining the price that a farmer obtains for per gallon of milk. The information may be used to analyze the diet of the cattle. For example, changes in the fat content may indicate an imbalance in the forage-to-concentrate ratio in the feed, a low total protein level may indicate a dietetic energy deficiency, a somatic cell count and a blood count may be used as diagnostic indicators of a specific clinical state of the cow, fluctuations in lactose content may indicate the presence of mastitis, etc.
Several methods for performing milk analysis are known. For example, the use of near infrared (near IR) spectroscopy for analyzing milk has been known for almost 15 years. In the article “Near Infra-Red Spectroscopy for Dairy Management: Measurement of Unhomogenized Milk Composition” by R. Tsenkova et al., published in Journal of Dairy Science, Vol. 82, pp. 2344-2351, 1999, which is incorporated herein by reference, there is proposed a method whereby the milk content is spectroscopically analyzed in the near IR range of from 400 nm to 2500 nm.
Further descriptions of methods of milk analysis using near IR spectroscopy are given in the articles “Fresh Raw Milk Composition Analysis by Near IR Spectroscopy” by Z. Schmilovitch et al, published in Proceedings of the International Symposium on the Prospects for Automatic Milking, Wageningen, Netherlands, EAAP Publication No. 65, pp. 193-198 (1992), and “Low Cost Near Infra-red Sensor for On-line Milk Composition Measurement” by Z. Schmilovitch et al., published in the Proceedings of the XIV Memorial CIGR World Congress, 2000, Tsukuba, Japan, which are incorporated herein by reference.
A number of known instruments and systems for performing milk analysis using near infrared (Near IR) spectroscopy are also known. For example, U.S. Patent Publication 2006/0092422, published on May 4, 2006, discloses a device for analyzing a non-limpid medium. The device illuminates the medium by at least one light pulse, acquires a spectral and temporal transmission image from the lit medium, and processes the image and derivatives thereof so as to acquire information about the non-limpid medium. The disclosure relates to the analysis of diffusing and absorbing media, for example milk.
Another example of milk analysis is disclosed in International Patent Publication WO/2003/040704, which is incorporated herein by reference, and discloses a near IR spectroscopy fluids analyzing system using a series of light emitting diodes (LEDs), each having a preselected center wavelength as illumination sources. The wavelengths have overlapping spectral widths, such that the measurement covers a broad spectrum. The LEDs sequentially illuminate the fluids sample. Subsequently, the transmission absorbance through the sample and the reflectance or scattering from the sample is measured for the wavelength range of each LED. The measurements are performed using photodetectors. The concentrations of component parts of the fluids are expressed in the form of a polynomial, which is a function of the measured transmitted, reflected intensities, or both, and of empirical coefficients, which are extracted by prior statistical analysis on measured intensities obtained from a large number of test samples having known concentrations of the component.
Though such systems and devices allow the analysis of fluids, such as milk, there is a need for a relatively inexpensive solution that can provide new advanced capabilities for measuring the presences of various component parts of a portion of such as milk.